Battery charger



FIG. 1 is a perspective view of a battery charger showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines shown in the drawings are included for the purpose of illustrating unclaimed portions of the battery charger and form no part of the claimed design. 

The ornamental design for a battery charger, as shown and described. 